Electrical relay having a reed switch



W. F. BARTON ELECTRICAL RELAY HAVING A REED SWITCH Feb. 7, 1967 2 Sheets-Sheet 1 Filed Dec. 21, 1964 f m 0, h w Z a 4 w %//M/ J 7 W i W i@ w a; KMMM Feb. 7, 1967 w. BARTQN 3,303,446

ELECTRICAL RELAY HAVING A REED SWITCH Filed Dec. 21, 1964 2 Sheets-Sheet 2 .zyfa W30 3, 0

United States Patent 3,303,446 ELECTRICAL RELAY HAVING A REED SWITiIH William Forbes Barton, Rolling Meadows, Ill., assignor to Grigsby-Barton, Inc., a corporation of Illinois Filed Dec. 21, 1964, Ser. No. 419,829 6 Claims. (Cl. 335296) This invention relates to a read relay including a reed switch formed of two or more elongated reeds or contact members of magnetic material having overlapping end portions disposed within a tube of insulating material such as glass and projecting in cantilever fashion from opposite ends of the tube, the other end portions of the reeds extending through the tube ends. The overlapping ends of the reeds are shifted into and out of conducting engagement with each other in response to selective direct current energization of a coil encircling the tube and the overlapping ends.

The primary object of the invention is to provide a relay of the above character having a novel construction adapted to be employed for a number of different ratings and which facilitates the connection of the relay parts into the electrical circuit and which protects the parts from moisture or other foreign matter.

Another object is to divide the relay into subassemblies in a novel manner to reduce the number of parts necessary to be stored for relays having different ratings.

' A further object is to provide a novel relay construction facilitating encapsulation in a moisture-proof material.

A more detailed object is to provide the coil and the connectors for exterior circuits and their supporting parts in a novel subassembly adapted to receive and be con nected quickly and easily to switches having different ratings.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings in which:

FIGURE 1 is a perspective view of a relay embodying the novel features of the present invention;

FIG. 2 is a bottom plane view of the relay;

FIG. 3 is an enlarged perspective view of the bobbin for the coil;

FIG. 4 is an exploded perspective view of a subassembly of the bobbin and coil with a terminal flag in position to be assembled to the bobbin;

FIG. 5 is a perspective view of the terminal board;

FIG. 6 is a side elevational view of the terminal board with two terminal pins in place;

FIG. 7 is an enlarged fragmentary vertical sectional view of the terminal board and one of the pins;

FIG. 8 is an exploded view showing the relation of the coil and bobbin subassembly to the terminal board prior to their assembly;

FIG. 9 is an end view of the parts of FIG. 8 in assembled relation;

FIG. 10 is a side elevational view of the subassembly of FIG. 9 with a reed switch in position to be inserted in the bobbin;

FIG. 11 is a view similar to FIG. 9 and showing a subsequent assembly operation;

FIG. 12 is a side elevational view of a bobbin of a modified construction;

FIG. 13 is a top view of the bobbin of FIG. 12; FIG. 14 is an end view of the bobbin of FIG. 12;

3,303,446 Patented Feb. 7, 1967 FIG. 15 is an enlarged side elevational view of a terminal flag of the modified construction;

FIG. 16 is a side elevational View of a terminal board for a difierent type of terminal flag in the modified construction;

FIG. 17 is a fragmentary sectional view taken along the line 1717 of FIG. 16;

FIG. 18 is a side elevational view of an additional flag of the modified relay construction;

FIGS. 19 and 20 are side and bottom elevational views, respectively, of the completed modified relay;

FIG. 21 is a fragmentary side elevational view of a modified bobbin construction; and

FIG. 22 is a fragmentary top elevational view of the bobbin of FIG. 21.

While preferred embodiments of the invention are shown in the drawings and will be described in detail herein, it is to be understood that the is no intention to be limited by such disclosure. Rather, it is the intention to cover all alternative constructions and modifications coming within the spirit and scope of the invention as defined in the appended claims.

In general, the present invention relates to a relay 24 of the type comprising a reed switch 25 (FIG. 10) having two or more flat strips or reeds 26 of magnetic material supported by and enclosed within a hollow tube 27 of insulating material such as glass. The ends of the tube are sealed around intermediate portions of the reeds which, at their adjacent or inner ends, project in cantilever fashion from the tube ends and into overlapping relation. At their remote or outer ends, the reeds project axially beyond the ends of the tube. In one form of switch shown in FIG. 10, the reeds are positioned initially with their overlapping ends spaced apart and magnetic flux resulting from energization of a coil 28 threads a path through the reeds and the gap between them to attract the reeds into contact with each other. As is well known in the art, additional reeds may be utilized to provide both a normally open and a normally closed set of contacts within the same tube. Also, a set of contacts may be biased magnetically into a normally closed condition for release to move to an open condition in response to energization of the coil.

The present invention contemplates :a novel assembly of the reed switch 25, the coil 28 and supporting parts to simplify the assembly and facilitate the use of the relay 24 as well as protect the switch and coil from damage. To this end, the coil, its support 29 and external terminal pins or posts 30 and 31 for the coil and the switch constitute a subassembly (FIG. 10) which is adapted for final assembly with any of a plurality of switches having different ratings. In the final assembly, the outer ends of the reeds are connected permanently to the associated posts and, after these connections are made, the entire assembly is encapsulated within a body 32 of hardenable sealing material so as to protect the switch, coil and connections while leaving the pins and posts exposed for connection into electrical circuits.

In accordance with the invention, the support 29 is a bobbin having an elongated core 33 with end flanges 34 projecting radially and outwardly from its ends and a central opening 35 extending throughout its entire length. The opening receives the switch 25 and is cylindrical in the present instance with a diameter slightly larger than the outside diameter of the tube 27 of the receive a pin.

switch. The coil 28 is wrapped around the core within the periphery of the flanges and the length of the core is correlated with and slightly less than the length of the switch so that, with the switch centered lengthwise in the core opening, the outer ends of the reeds 26 extend a short distance beyond the ends of the core.

For convenience of connection into electrical circuits, the terminal posts 31 and pins 30 preferably project in the same direction and laterally from one side of the core. The pins are connected to the coflends or terminals 35 and, in one form shown FIGS, 1 to 11, are supported by a terminal board 36 of insulation material. The terminal posts 31 are connected individually to the outer ends of the respective reeds 26 and extend through apertures 37 in the board.

Assembly of the parts and connection of the reeds 26 to their posts 31 is facilitated by forming the posts as integral projections from flat flags 38 which interflt with cooperating parts on the bobbin 29'. Thus, the flanges 34, adjacent their outer sides which face axially away from the core, are formed with grooves 39 which are laterally spaced apart and face toward each other along the outer sides of the flanges to receive opposite edges of the flags. In this instance, each flag is of rectangular shape and the space including the grooves for receiving it is of a complementary size and shape to provide a snug or friction fit, the flag receiving recess defined by the walls of the grooves and flat outer side of each flange being of T-shaped cross section. Each flange herein also is of rectangular shape with the grooves paralleling opposite outer edges of the flanges.

Where, as in this instance, the bobbin 29 is formed by molding a suitable thermosetting resin such as nylon, a tighter fit may be achieved by inserting each flag in its grooves While the flanges are still hot from the molding operation so that, as it cools, the plastic tightens around the flag edges. Inter-locking may be enhanced further by notching the edges as indicated at '40, bevels 41 being formed on the entering corners of each flag to facilitate entry into the grooves; V

The terminal board 36 is a sheet of insulating fiberboard of flat rectangular shape and fits against corresponding flat sides of the flanges 34 on the bobbin 29. The length and width of the board are coextensive with the length and width of the bobbin so that the'ed'ges of the flanges are flush with the edges of the board. To utilize the flags to hold the board against the flanges prior to encapsulation, an intermediate portion 42 of each flag adjacent the post 31 is made larger than the post but smaller than the main section of the flag. Also, the corresponding aperture 37 in the board is of complementary shape permitting the intermediate portion to be staked against the opposite side of the board as indicated at 43 (FIGS. 9 and and hold the board against the main section.

The pins 30 for the coil ends 35 are assembled to the terminal board 36 prior to attachment of the board against the bobbin flanges 34. To accommodate different coil configurations such as a center tapped coil for a plurality of coils, the intermediate portion of the board is formed with a plurality of holes 44 each adapted to There being only one coil 28 with two ends in this instance, only two pins are shown. Each pin is formed as a hollow tube having a shoulder 45 to engage the outer side of the board, the upper end of the tube being bent over against the inner side of the board as indicated in FIGS. 7 and 8 to attach the pin to the board. Connection of each coil end to its pin is effected by inserting the end into the pin and applying a liquid solderto the two as by forming ian aperture in the end of the pin and dipping it in a solder bath.

The subassembly of the bobbin 29, coil 23, flags 38, pins 30 and terminal board 36 is adapted to receive any of a plurality of differently rated reed switches 25 by forming each flag with a hole or open portion 46 registering with the core opening 35 to permit insertion of the reed switch after the subassemb'ly is completed. By forming a hole in each flag, the flagsmay be interchangeable and the switch may be inserted from either end of the core. To form the electrical connection between each reed 26 and the associated flag and also close'the ends of the core opening, a washer 47 (FIGS. 10 and 11) larger than the flag hole is te-lescoped over the outer end of the reed and is secured by solder 48 to the reed and flat against the outer side of the flag. After these connections are made, the entire assemblyis encapsulated in the sealing material 32 which, in this instance, covefs all parts except the outer ends of the terminal posts and pins 31 and 3t and seals the parts effectively, the Washers, solder, and the fit of the flags against the outer sides of the flanges preventing entry of the material into the core opening. Herein, the sealing material is a suitable epoxy resin.

Reviewing the assembly of the relay 24, the flags 38 are inserted into the grooves 39 of the bobbin flanges 34 after the bobbin 29 has been molded. Then, after the coil 28 has been wound on the core 33 and the coil pins 30 have been secured in their holes 44 in the terminal board 36, the coil ends 35 are inserted in the pins and secured thereto by solder. The subassembly f bobbin, coil, board, pins and flags then is completed by extending the posts 31 and intermediate portions 42 of the flags through the slots 3'7 in the board and then staking the intermediate portions at 43 to hold the board flat against the edges of the flanges. The subasse'r'nbly thus is ready to receive any of a plurality of differently rated reed switches 25. Such a switchis simply inserted into the core opening 35 and through one of the flag holes 46 and the washers 47 are telescoped over the outer ends of the reeds 2'6and are soldered to both those ends and the flags. Finally, the relay isc'ornpleted by enclosing the final assembly in the eiieapsiilating friaterial Insteadof mounting the coil pins 30" in a terminal board as in FIGS, 1 to ll, they may bemojintedip the flanges 34' as in the modification of FIGS. 12 th 20 the parts 'of this modification which correspond t'ti parts pie viously discussed bearing similar but primed reference numbers. This modification contemplates a so called form C reed switch (not shown) having a single reed projecting from the center of the tube'atohee'rld and two reeds projecting from the opposite end; The single reed normally engages one of the pair to form ntirrhalfi closed contacts and is normally spaced from theotli r of the pair to form normally open contacts. As in the first form, the terminal pos't 31" for the siriglereedat one end is secured to and projects from a flag 38 which fits into grooves 39' and lies against the adjacent outef side of one of the'bobbin flanges 34'. This flag has a. single hole 46 to receive the entire switch and the single reed which is soldered to a washer (not shown) and to the flag in the final assembly, as in the first form.-

At the other end of the bobbin, however, are two tei' minal posts 50 for the respective reeds of the pair. These posts are integral with smaller flags 51 soldered to the respective reeds which extend through small apertures 52 in the flags. The apertures are too small to receive the tube of the switch and each flag has a circular periph ery slightly larger than the aperture with a thin elongated intermediate section 53 joining the circular portion to the post and having the same thickness and width as the post.

The smaller flags 51 are supported by a sheet 54 of insulating material which fits in the grooves 39 and against the outer side of the other bobbin flange 34' like the larger flag 38. Apertures 55 in the sheet receive a pair of small grommets 56 which extend through the small flags and secure them to the sheet as well as receive the pair of reeds, the reeds being soldered to the grommets and flags in the final assembly before encapsw lation. To assist the grommets in positioning the small flags with respect to the supporting sheet, the intermediate portion of each small flag has a laterally ofiset post fitting into a slot 57 in the sheet and locating the post 50 in the plane of the sheet.

To accommodate the pair of reeds which are offset from the center of the reed switch tube in the modified relay 24 of FIGS. 12 to 20, grooves 58 are formed along opposite sides of the core opening 35'. They extend throughout the length of the opening to permit insertion of either end of the switch into either end of the opening.

The modified terminal pins 30' for the coil connections project integrally from small'flags 59 which fit frictionally in slots 60 opening outwardly from corresponding edges of the flanges 34' of the bobbin 29'. To accommodate a plurality of these slots for different numbers of flags depending on the coil connections desired, the modified flanges are somewhat thicker than those of the first form. The connection between each coil end and the associated small flag 59 is efiected by wrapping the coil end around the flag and soldering it to the flag. To insure that each flag is retained in its slot prior to encapsulation, opposite edges of the flag preferably are serrated as indicated at 61. Instead of being aligned longitudinally as in the first form, the pins 30' and posts 31' and 50 of the modification are offset transversely at each end of the bobbin as shown in FIG. 20.

As in the first form, the modified bobbin 29' with its encircling coil (not shown), the reed switch flags 38' and 51, the posts 31' and 50', and the coil pins 30" with their flags 59 all may be put together as a subassembly to accommodate difiFerent switches. When it is desired to complete the assembly, the switch is inserted in the core opening and the reeds are soldered to their respective flags. Finally, the assembly is encapsulated to protect the parts while leaving only the pins and posts exposed.

If it is desired to use a magnetic bias which maintains one condition of the reeds 26 with the coil 28 de-energized but which is overcome upon energization of the coil to change the condition of the reeds, this may be accomplished easily in the improved assembly by the provision of a bar magnet 62. Such magnet is polarized longitudinally and simply is placed within a recess 63 which extends longitudinally of the core 33 and opens radially and outwardly therefrom as shown in FIGS. 21 and 22. The bar is inserted in the recess prior to winding of the coil and is held in place by the coil. Its end to end polarization depends on the type of switch to be used and the desired action in response to energization and de-energization of the coil.

It will be apparent from the foregoing that the subassembly including the bobbin 29, coil 28, and terminal pins 30 and posts 31 may be formed quickly and easily with few manual operations and with different selected coil configurations and connections. Further, versatility is achieved because each of the different subassemblies may be used with a selected one of different switch arrangements to provide a wide variety of available types of relay operation. By the provision of the subassemblies, it is possible to provide such a wide variety while keeping inventories relatively small. In addition to adaptability to different switches, the 'subassemblies contribute to a simple final assembly with the switches and encapsulation with all terminal pins and posts projecting in convenient locations from the final unit.

I claim:

1. For use in forming a relay having a reed switch with an elongated sealedtube of insulating material and a pair of reeds of conducting material extending beyond the ends of the tube, the combination of a bobbin of insulating material having a core with an axis and a central coaxial opening extending along and throughout the length of the core to receive said tube, a coil encircling said core and having terminals, flags of conducting material mounted on said bobbin at opposite ends of said core and having parallel terminal posts projecting laterally from one side of the core, at least one of said flags having an open portion aligned with said bobbin opening and being large enough to permit endwise insertion of said tube into said bobbin opening, and terminal pins secured to said bobbin and projecting laterally from said core side in parallelism with said posts, said pins being connected individually to said coil terminals.

2. For use in forming a relay having a reed switch with an elongated sealed tube of insulating material and a pair of reeds of conducting material extending beyond the ends of the tube, the combination of a bobbin of insulating material having a core with an axis and a central coaxial opening extending along and throughout the length of the core to receive said tube and flanges projecting radially and outwardly from opposite ends of the core and having outer sides facing axially and away from the core, a coil encircling said core within the peripheries of said flanges and having terminals, flags of conducting material mounted on said outer sides of said flanges and having parallel terminal posts projecting laterally from one side of said core and beyond the peripheries of said flanges, at least one of said flags having a central aperture aligned with said opening and being large enough to permit endwise insertion of said tube into said bobbin opening, and terminal pins secured to said bobbin and projecting laterally from said core side in parallelism with said posts, said pins being connected individually to said coil terminals.

3. The combination of claim 2 in which the outer sides of said flanges are formed with grooves laterally spaced apart and opening toward each other to receive said flags and at least one of said flags is secured to a terminal board of insulating material lying against said outer side of one of said flanges.

4. The combination of Claim 2 in which said flanges are formed with slots opening laterally of said core axis in parallel with said flags and said terminal pins are integra-l projections formed on other flags fitting into said slots.

5. For use in forming a relay having a reed switch with an elongated sealed tube of insulating material and a pair of reeds of conducting material extending through the ends of the tube, the combination of a bobbin of insullating material having a core with an axis and a central coaxial opening to receive said tube and flanges projecting radially and outwardly from opposite ends of the core and having outer sides facing axially and away from the core, a coil encircling said core within the peripheries of said flanges and having terminals, a flat elongated terminal board extending longitudinally of said core and spanning and lying against corresponding edges of said flanges on one side of the core, flat flags lying and secured against said outer sides of said flanges and having parallel terminal posts projecting laterally of said board through apertures in opposite ends of the board and beyond the opposite side of the board, said flags having upset portions securing said board to said flanges, and terminal pins projecting through said board in parallelism with said posts and connected individually to said coil terminals, at least one of said flags having an aperture large enough to receive said tube and aligned with core opening to permit endwise insertion of the tube into the opening after assembly of the flags in said grooves.

6. For use in forming a relay with a reed switch having an elongated sealed tube of insulating material and a pair of reeds of conducting material extending beyond the ends of the tube, the combination of a bobbin of insulating material having a core with an axis and a central coaxial opening to receive said tube and flanges projecting radially and outwardly from opposite ends of the core and having outer sides facing axially and away from the core, means an said outer sides of said flanges defining grooves laterally spaced apart and opening toward each other, a coil encircling said core within the peripheries of said flanges and having terminals, a flat elongated terminal board extending longitudinally of said core and spanning and lying against corresponding edges of said flanges on one side of the core, fiat flags lying against said outer sides of said flanges and having edges fitting friction-ally within said grooves and parallel terminal posts projecting laterally of said board through apertures in opposite ends of the board and beyond the opposite side of the board, said flags having upset portions securing said board to said flanges and central apertures adapted to receive said reds of said switch, and terminal pins projecting through said board in parallelism with said posts and connected individually to said coil terminals, at least one of said flag apertures being large enough to receive said tube to permit endWise insertion of the tube into said bobbin opening after assembly of the flags in said grooves.

References Cited by the Examiner UNITED STATES PATENTS OTHER REFERENCES I Bolan, P. S., IBM Technical Disclosure Bulletin, Mu tip-1e Reed Switch, vol. 4, No. 7, page 37, December 1961.

BERNARD A. GILH-EANY, Primary Examiner.

J. J, BAKER, Assistant Examiner. 

1. FOR USE IN FORMING A RELAY HAVING A REED SWITCH WITH AN ELONGATED SEALED TUBE OF INSULATING MATERIAL AND A PAIR OF REEDS OF CONDUCTING MATERIAL EXTENDING BEYOND THE ENDS OF THE TUBE, THE COMBINATION OF A BOBBIN OF INSULATING MATERIAL HAVING A CORE WITH AN AXIS AND A CENTRAL COAXIAL OPENING EXTENDING ALONG AND THROUGHOUT THE LENGTH OF THE CORE TO RECEIVE SAID TUBE, A COIL ENCIRCLING SAID CORE AND HAVING TERMINALS, FLAGS OF CONDUCTING MATERIAL MOUNTED ON SAID BOBBIN AT OPPOSITE ENDS OF SAID CORE AND HAVING PARALLEL TERMINAL POSTS PROJECTING LATERALLY FROM ONE SIDE OF THE CORE, AT LEAST ONE OF SAID FLAGS HAVING AN OPEN PORTION ALIGNED WITH SAID BOBBIN OPENING AND BEING LARGE ENOUGH TO PERMIT ENDWISE INSERTION OF SAID TUBE INTO SAID BOBBIN OPENING, AND TERMINAL PINS SECURED TO SAID BOBBIN AND PROJECTING LATERALLY FROM SAID CORE SIDE IN PARALLELISM WITH SAID POSTS, SAID PINS BEING CONNECTED INDIVIDUALLY TO SAID COIL TERMINALS. 